Now we are returning to the winemaking cellar, where the alcoholic fermentations are by now all complete and all of the wine has been separated from the marc. At this time we are about to face one of the most delicate moments, which is the second fermentation, called malolactic fermentation. What is malolactic fermentation? It is the transformation of the fragile malic acid bacteria, a very sour acid, into lactic acid, a more delicate acid. For red wines, this fermentation is normally induced and one tries to complete it immediately after the alcoholic fermentation. The ideal conditions favouring malolactic bacteria are: Low sulphur content, temperature higher than 18°C and little oxygen.
Malolactic fermentation is a process that, if not controlled, carries the risk of occurring in the bottle with consequential deposits, strange smells and wine that unexpectedly fizzes at the first warmth of spring. It is a slow and silent fermentation, worked by highly sensitive bacteria, and for this reason it is difficult to manage and control.
The heating of the winemaking cellar is therefore fundamental, and it is because of this that in the past we invested a great deal of money in the thermal conditioning of the locales, although always with an eye towards the environment, and I will talk about this in the next posts….